[A case of primary mediastinal (Thymic) B-cell lymphoma successfully treated with the DA-EPOCH-R Regimen].

Abstract Primary mediastinal (thymic) B-cell lymphoma (PMBL) is resistant to treatment when compared with diffuse large B-cell lymphoma (DLBCL). Moreover, the optimal first -line treatment of PMBL has not yet been determined. Herein, we report a case of PMBL that was successfully treated with the dose adjusted (DA) etoposide, prednisolone, vincristine, doxorubicin, and cyclophosphamide with rituximab (EPOCH-R) regimen. A-29-year-old woman was referred to our hospital with an anterior mediastinal tumor. Eight months before admission, she had visited a clinic for pain in the chest and back, but no abnormalities were found. Subsequently, her chest pain got worse, and she went to another clinic, where she was detected with an anterior mediastinal tumor and was referred to our hospital. Tumor biopsy with a thoracoscope was performed, and a diagnosis of PMBL was made. The tumor diameter was 90 mm, with invasion to the lungs and superior vena cava. The tumor had a clinical stage of IEA, and the International Prognostic Index (IPI) was low risk. She was treated with the DA-EPOCH-R regimen for 8 courses, and a complete response was achieved. A recent retrospective study of DA-EPOCH-R treatment without radiotherapy for PMBL was recently published. It showed that the event-free survival rate was 93% and the overall survival rate was 97% during a median 5-year follow-up. Thus, DA-EPOCH-R may be a potential standard treatment for PMBL.